The invention relates to a cooling air flap and blower control for motor vehicles, especially high performance passenger automobiles of the type having an engine radiator cooling air stream generated by movement of the vehicle, with controllable flaps for controlling the flow of air in response to certain vehicle operating conditions.
Recent developments in motor vehicles, especially automobiles, in very recent times have increasingly reflected the standpoint of optimal aerodynamic design, especially to increase driving performance and reduce fuel consumption. One important factor in this regard is the throughflow required through the engine compartment to cool the engine, which has a negative effect on the so-called coefficient of air resistance. It is also desirable for the engine, following a starting procedure from the cold state, to warm up rapidly to an operating temperature at which it can operate with optimum economy and service life, and to keep the latter as constant as possible during operation.
German OS No. 32 11 793 teaches a coolant temperature regulatinig system for a motor vehicle engine which, in addition to the conventional coolant temperature regulation using a thermostat in a bypasss circuit for the coolant for the engine and the cooling air blower which is switched on and off by a thermostat, additionally controls a shutter in an opening in the car body through which cooling air flows.
It is true that this deals with the requirement to improve aerodynamics. However, the controlling elements used all exhibit more or less of a two-point characteristic so that the operating temperature of the engine cannot be kept constant at a required level. The resulting constant fluctuations around a set operating point produce a poor quality of regulation and hence load and wear on the engine, including all the assemblies and parts traversed by the cooling water. In addition, the adjusting element of the shutter, which is designed as an element made of expanding material and is affected only by the coolant, cannot be set sufficiently accurately and permits no additional parameters to adjust the cooling air stream to the cooling air needs of the engine and auxiliary or additional assemblies.
To improve the quality of regulation, combined regulating systems with continually operating adjusting elements have been proposed "Motortechnische Zeitschrift", Volume 20, No. 5, May 1959, pages 141 to 142. These hydraulically or hydrostatically operating systems however, are extremely cumbersome and expensive; their use is admissible only when the internal combustion engine already has a pressurized oil supply. Another problem is the compressed oil leaks which are always present in hydraulic or hydrostatic systems.
U.S. Pat. No. 4,133,185, to Robert B. Dickey, relates to an automatic air circulation control, including air inflow shutters. U.S. Pat. No. 4,546,742, to Fred D. Sturges, also discloses controllable radiator shutters in a temperature control system for internal combustion engines.
An object of the invention is to provide an improved coolant and blower control for motor vehicles which optimally regulates the temperature environment of an internal combustion engine including its auxiliary and additional assemblies of acceptable cost and also fully takes into account the aerodynamic aspects of the motor vehicle.
The advantages of the invention lie primarily in the fact that a cooling air flap and blower control for motor vehicles is provided which controls the cooling air requirements of an internal combustion engine of a motor vehicle including all auxiliary and additional assemblies with outstanding quality control. In addition, it is readily adjustable to varying conditions in different types of motor vehicles in internal combustion engines, requires only a small amount of room for installation, and is inexpensive to manufacture and install.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings(s) which show, for purposes of illustration only, an embodiment/several embodiments in accordance with the present invention.